Work arm sewing machine



Aug. 1, 1944. I F.1LuTz, 2,354,819

WORK ARM SEWING MACHINE Filed 001;. 12, 1940 y 4 Sheets-Sheet 1 ATTORNEYS.

fAug. 1, 1944.

WORK ARM SEWING MACHINE` Filed Oct. 12, 1940 4 SheetSSheet 2v J f B1 H'WITNBSSES.- f f INVENTOR:

- ,/M l Frederick Luisg,

A TTORNE YS.

F.A LuTz 2,354,819

4 Sheets-Sheet 5 Filed Oct. 12, 1940 WORK l ARM SEWING MACHINE Q R S4@ nyu/ ENTOR- 'redeLc/f Lui/ 9) ATTORNEYS.

Aug.' 1, 1944. F. 'UTZ 2,354,819

v. WORK ARM SEWINI MACHINE Filed Oct.,12, 1940 4 Sheets- Sheet 4 W I TNESSES: IN V EN TOR."

@MM/0@ l `ffrmueriif Lut@ )WM/@m B?" mm 4 TTORNE YS.

Patented Aug. 1, 1944 WORK ARM SEWING MACHINE.

Frederick Lutz, Stuttgart, Germany, @ssignor to Union Special Machine Company, Chicago, Ill.,

a corporation of Illinois Application October 12, 1940, Serial No. 360,857 In Germany October 18,- 1939 14 Claims.

This invention relates to sewing machines. More especially, it has reference to sewing machines such as are used in the seaming of tubular articles such as garment sleeves and the like, and'characterized by a work supporting arm along which the material is advanced incident to the sewing.

My invention is Vconcerned with improvements which favor greater simplicity and economy in the construction and assembling of sewing machines of the kind referred to, as well as higher speed operation for capacity to better meet modern requirements as regards increased output.

' One of the foregoing advantages is attained as hereinafter more fully disclosed, through operation of the needle and the associated or complemental stitch-forming element, i. e., the looper,

from a single or common rotary actuator on thel Another of the advantages is secured by so constructing and arranging the interposed linkages by which the feeding instrumentality of the machine is actuated, so that these linkages are in endwise tension during their active strokes, rather than in endwise compression as ordinarily, with the result that they can be made much lighter than heretofore.

An'otherof the foregoing advantages is attained through constructionof the work supporting arm as an integral part of the machine base, while the needle arm is separately formed and secured to` the base in such a way that not only is the machining of the frame greatly expedited and the cost thereof materially reduced, but theassembling with it ofthe moving parts correspondingly facilitated.

rAnother advantage results from the yformation of the machine frame with an oil-tight hollow in which Athe moving parts directly connected to the drive shaft are enclosed for the purpose of automatic lubrication by splash action, and with which a hollow in the work arm directly communicates so that the parts within it are also lubricatedinthe same way. y

Other objects and attendant advantages will cated by the angled arrows V'-V in Figs. 2 and 4. f

Fig. 6 is a transverse sectional view of the machine, taken as indicated by the' angled arrows VI-VI in Figs. 2 and 4.

Fig. 7 is a fragmentary View in cross section, taken as indicated by the angled arrows VII-VII in Figs- 2 and 4 and Fig. 8 is a fragmentary detail sectional view, looking as indicated by the angled arrows VIII-VIII in Fig. 7.

With more specic reference to these illustrations, IIJ designates the base of the machine which is hollow and of rectangular box-like conf figuration, and with which, in accordance with my invention, the horizontal tubular work supporting arm II is integrally formed. Mounted on the top of the base IU and removably secured by screws I2, is the standard portion .I3 of a needle arm I4 which overreaches the Work supporting arm II, and which at its free end terminates in a needle head I5. Integrally formed with the standard portion I3 of the arm I4, likewise in accordance with my invention, is a hollow upright laterally-offset column I6 which is of square cross-section and in effect constitutes an upward continuation of the hollow in `the base I0, as shown in Figs. 2 and 6. The interiors of the base I0 and the column I6 are accessible upon removal of the screw-secured side and top cover plates respectively designated I'I and I8. From Figs. 2 and 6, it will be also observed that'the lower part of the base I0 is utilized as a sump in 'f which a supply of lubrineedle head I5 is a bar 22 whereto is secured, at the lower end, a needle 23 which is adapted to pass up and down through a throat plate 24 at the outer end of the work supporting arm Il. Through a link shown at 25 in Fig. 3, the needle bar 22 is connectedtoan arm 26 clamped on the front end of a rhorizontal oscillating or rock shaft 21, which is journaled in a bearing 28 on the needle head I5, and which extends rearward through a fixed bearing 29 in the front wall of the column I6 into the hollow of the latter.V The.l

needle head I5 also affords another pair of vertically-spaced apertured guide lugs 38. and 3| for a presser bar 32 which carries a presser foot 33 at its lower end. The presser bar 32 is subject to the downward pressure of a leaf spring 35, which, at its anchorage end, is supported by aA projection 36 on the needle arm I4 and which is regustitch forming and feeding instrumentalities of the machine all derive their movements from a drive shaft 6I, which, see Figs. 4 and 6, extends crosswise `of the machine base I8 and which is journaled in bearings 62 and 63 in the side walls of said base. On one of the protruding ends of the drive shaft EI is mounted a combined hand and belt wheel 64 whereby the machine may be either manually or power operated. At its other protruding end, the drive shaft carries the rotor 65 of a suitable looper thread control means comprehensively designated by the numeral 66 in Fig. 4. Since this thread-control means, per se, does not constitute a part of the present invention,

latable by a thumb screw 31. The presser foot 33 held normally in contact with a stop stud 44 on the needle head I5.

Arrangedv to cooperate with the needle 23 in stitch formation within the freefend of thework supporting arm II is a complemental instrumentality in the form of a looper. 45, see, Fig. 2,V which is accessible upon removal of the closure cap shown at 46. As shown, thislooper 45 is adjustably secured on the outer Aend of va horizontal shaft-41 which. isjournaled, .with capacity for both oscillatory andiendwise'movement in bearf ings 48, 49 and 50, respectively within the hol-VV lowsof the base l andthe workisupporting arm II.

Incident to seamed is lintermittently progressed along the workvsupportingarm Il by afeed dog 5I, the toothed portions of which operate upwardly through slotsin the throat plate 2.4'in a well known'fmanner.H As shown, the feed dog. 5I. is

affixed tothe distal end of a horizontal4 bar 52 within the work supporting arm I I. Immediately inward of thebearing 50 for the looper shaft 41, the feed bar. 52 is supportedby a pairof short vertical links 53 whereof the lower ends are pivotally connectedat opposite sides to the horizontal arm 54a of a bell crank 54,'.which is capable of .oscillation about a'transverse, pin 55 engaged atits ends in upstanding laterally-spaced lugs 55 at the bottomof the workarm II, see Figs. 2, 4 and 5. From Fig. 5 it willbe noted that the central portion of the pin 55 on;which th e bell crank- 54 is mounted is eccentric to the ends for a purpose later explained..r At itsrear endthe feed theV sewing, thegmaterial being Y no further reference need be made thereto here- Y Immediately inward of the bearing 62, the drive shaft 6I is formed with a crank 61 having a spherical surface 68 embraced by the lower end of a vertically disposed pitman 69. As shown in Figs. 2 and 6, the pitman 69 extends upward in the communicating hollows of the base Illv and column I4, and, at its top, embraces a ball, 16a at the end of an arm 10 which is clamped to the rear (left hand in Fig. 2) end of the needle shaft 21. Through these provisions, it will be seen that the needle shaft 21 is oscillated for transmission of the necessary reciprocatory movements to the needle bar22, and moreover that the pitman 69 is in endwise tension as the active or fabric piercing strokes are imparted' to the needle, wherefore said pitman can be made comparatively light since it is not subjected under these circumstances to lateral flexure.

A second spherical surface 1I on thecrank 61 of the drive shaft 6I is embraced by the lower end of another but shorter vertical pitman or link 12 whereof the upper end in turn embraces a ball Surface 13a on a crank 13 formed on the looper lshaft 41 in the interval between, the bearings 48 and 49 for the latter, see Figs. 2, 4 and 6. As a consequence, it will be seen that the loopershaft 41 is oscillated for impartation of needle thread lloop taking and shedding movements to the looper 45 incident to stitch formation. Thus, 'the oscillating movements of both the needle shaft 21 and the looper shaft 41 are, in accordance with my invention, derived from a common rotary actuator on the drive shaft of the machine.

Immediately. inward ofthe bearing 63,` the drive shaft 6I is further provided with a ball eccentric 15 which is embraced by one end of'a horizontal strap. link 16 whereof the'other end is connected to' apivot 11 adjustable along the pendent extremity 18a of a double armed rocker 18. As shown in Figs. 2, 7 and 8, the rocker 18 is freely fulcrumed onan axle pin 19 extending crosswise of the hollowof the basei and held against endwiseshifting on said pin .between a bar 52 is supported by virtue of being pivotally connected to the upward yoke. arm 51a of a bell v Through connections about'to be described, the'v` pair of positionally-adjustable collars 80 and 8|. The upwardly extending extremity 18h of the rocker 18 provides a socket for a ball 82 (Fig. 8) which'is pierced for passage of a sleeve 83 rockvable and axially shiftable on a cylindrical arm 84 on the looper shaft 41 (Fig. .7), the fulcrum hub Y of said arm being freely held between adjustable collars 85H and 86 r(Fig. 2) on said shaft.. As a consequence ofy the vimmediately foregoing arrangement, the looper shaft 41 is reciprocated two additional, adjacently-disposed ball eccentrics 81 and 88. The strap link 89 of the eccentricI 81 isconnected at its outer end to a pivotV porting arm I'I and pivotally connected at itsv distal'end to a vertical arm 54h of the bell crank 54,'130 induce, through said bell crank, the neces-v sary rise andfall movements in the feed bar 52. By rotatively adjusting the pin 55, it will be apparent from Figs. 2 and 7 that the sphere of the feed' rise may be varied as may be desired or required. lt is to be especially noted here that during the active or fabric-advancing and concurrent rise movements of the feed dog 5I when the latter is opposed byA the presser foot, the feed bar 52 and the link 9| are both under lengthwise tension. Thus these parts, too, can be made much lighter than ordinarily.

In order to stabilize the movements of the drive shaft El, in its rotation, Vthe latter is dynamically balanced by a counterweight shown at 93. Attention is directed to the fact that the drive shaft 6l is journaled low in the base lll well beneath the level of the looper shaft 41, the feed bar 52 and the other parts which arekactuated from it. As a consequenceof this, the simplification of the machine and the use of fewer and lighter moving parts, higher speed operation is made possible with absence of vibration.

During the operation of the machine, the lower. ball socket ends of the strap arms or links 69 and T2 and the counterweight 93 dip into the oilsupply and disperse the oil within the communicating hollows of the base I0 and the column i6 to lubricate the various moving parts directly connected to the drive shaft 6|, as well as the ball joint at 15a and the bearing 29 in shaft and` extending lengthwise of the worksupporting arm; and a drive shaft intheframe extending c'rosswise of the needle shaft and the` looper shaft below them and having an eccentric actuator thereon from which said needle shaft and said looper shaft separately but simultaneously derive their oscillatory'movements.

the upper part of said column for the needle actuating shaft 2. Some of the splashed oil finds its way into the bearings 48 and 49 for the looper shaft ll'l, and also to the bearings 62 and 63 for the drive shaft Si by way of ducts 95 and 96; see Fig. 6, which lead into the tops of the latter bearings. From Fig. 6 it will be further noted that pockets 91 and 98 are provided in thev bearings E52 and 63 for retention of the trapped oil to insure adequate lubrication atl all times, said pockets being closed by screw plugs 99 and |00 respectively which can be removed 1n the event that clogging should occur. Some of the dispersed oil, moreover, enters the hollow of the work supporting arm Il to keep the parts enclosed therein properly lubricated also. l

The construction of the machine frame 1n two parts, as described, is obviously favorable to ready machining, particularly in view of the ease with which `access can be had to the hollows in the base lil and the column IE by way of the openings covered by the removable plates Il and it. IAssembling, with the frame, of the moving parts-islikewise greatly'facilitated through provision of the side and top openings, and by v1rtue ofl the fact that the bearing 62 for the drive shafttlr is made as a separable part of vthe machine oase it, as shown in Figs. 4 and 6.l

Having thus described my invention, I claim.: 1. A sewing machine comprising a frame with a work supporting arm along which the work is fed. and an overhanging needle arm; an oscil- '(5 2. A sewing machine comprising a frame with an work supporting arm along which the work is fed, and an `overhanging needle arm.; an oscillating needle shaft mounted on the needle arm;`

an oscillating looper shaft parallel with the needle shaft and extending lengthwise -of the work sup' porting arm; and a drive shaft in the frame ex-l tending crosswise of the needle shaft and thek looper shaft below them, having thereon an eccentric actuator in the form of a crank from which said needle shaft and said looper shaft separately derive their voscillatory movements.

3. A sewing machine comprising a frame with a work supporting arm along which the work is fed, and an overhang'ing needle arm; an oscillating needle shaft mounted on the needle arm;

an oscillating looper shaft parallel with the needle shaft and extending lengthwise of the work supi 4. A sewing machine comprising a framefwithf a work supporting arm along which the Work is fed, and an overhanging needle arm; an oscillating needleshaft mounted on and extending lengthwise of the needle arm; an oscillating looper` shaft parallel with the needle shaft and extending lengthwise of the work supporting arm; feeding means including a feed bar which extends'lengthwiseof the work arm; a drive shaft in the frame extending crosswisel of thef needleand looper shafts below themand having an eccentric actuator thereon from which the needle shaft and the looper shaft separately derive their oscillatory movements; andk another eccentric actuator on said drive shaft from which the feed bar is actuated.

5. A sewing machine comprising a lframe with a worksupporting arm along which the work is fedand an overhanging needle arm; an Voscillating needle shaft mounted on and extending lengthwise of the needle arm; an oscillating looperV shaft parallel with the needle shaft and extending lengthwise of the work supporting arm; feed- 4 ing means including a feed bar whichalso extends lengthwise of the work arm; a drive shaftin they, frame extending crosswise of the needle and,

looper shafts below them and having an eccentric actuator thereon fromwhich the .needle :shaft -and the looper shaft separately derive their oscillatory movements; another eccentric actuator on the drive shaft from whichendwiseor feeding movements ,are impartedto the feed bar; and a, third eccentric on said drive shaft from whichI rise and fall movements are communicated to said feed bar.

6. A sewing machine comprising a frame with a work supporting arm along which the work is fed, 'and an overhanging'needle arm; an oscillating needle shaft mounted on the needle arm; an oscillating looper shaft parallel with the needle shaftand extending lengthwise of Atheyvork supporting arm; a drive shaft in the frame extending crosswise of the needle shaft and the looper shaft below them and having an eccentric actuator`V thereon from which both Asaid needle shaft ,and said looper shaft derive -their oscillatory movements; another eccentric actuator on the drive shaft; and means connecting the last mentioned eccentric actuator with the feed bar so that the latter is in lengthwise tension incident tothe performance of its active or feeding stroke.

` .'l. A sewing machine comprising a frame witha work supporting arm' along which the workis fed,v and an overhanging needlearm; an oscillating needle shaft mounted on the needle arm; an oscillating looper shaft parallel with the needle shaft and extending lengthwise of the work supporting arm; feeding means including a feed bar which also extends lengthwise of the work supporting arm.; a drive shaft in the frame extending crosswise of the needle shaft and the looper shaft below them and having an eccentric actuator thereon from which both said needle shaft and said looper shaft derive their oscillatory movements; two additional eccentric actuators on the drive shaft; means connecting one Vof the additional rotary actuators with the feed bar so that the latteris in lengthwise tension incident to the' performance of its active or feeding stroke; and means including a strap link operated from the other additional rotary actuator for imparting rise anclvfall movements to the feed bar, said' link being also in lengthwise tension incident to communication ofthe lift movements tosaid feed bar.

8. A sewing machine comprising a frame with a` work supporting arm along which the work is fed, and an overhanging needle arm; an oscillating needle shaft mounted on and extending lengthwise of the needle arm; an oscillating looper shaft in the frame parallel with the needle shaft and extending lengthwise of the work supporting arm; a 'drive shaft below said looper shaft crosswise of the latter having an eccentric 2&5458 119i from one of said rotary eccentric actuators to the needle and looper shafts to simultaneously oscilactuator thereon; means connecting the needle and looper shafts to said eccentric actuator; and an oil-tight housing provided by the'frame and' enclosing the drive shaft and the parts directly connected thereto. f

9. A sewing machine comprising a frame with I a work supporting arm along which the work is fed; and an overhanging needle arm; a needle shaft mounted on the needle arm; a, looper shaft parallel With the needle shaft extending Ylengthwise of the work supporting arm.; a drive shaft journaled in the frame crosswise ofthe needle shaft and the looper shaft in a plane below the latter and having a rotary eccentric actuator thereon; and pitmans extending upward from said rotary actuator to the needle and looper shafts respectively to simultaneously operate said shafts.

10. A sewing machine comprising a frame with a work supporting arm along which' the work is fed, and an overhanging'needle arm; a needle shaft mounted on the needle-arm; a looper shaft parallel with the needle shaft extending lengthwise of the work supporting arm; adrive shaft journaled in the frame crosswise of the needle shaft and the looper shaft in a plane below the latter and having a pair of rotary eccentric actuators thereon; pitmans extending Yupward late said shafts; and a third pitman extending upward from the other rotary eccentric actuator to the looper shaft to impart endwise or needleavoiding movements thereto.

11. A sewing machine comprising a frame with a hollow base, a communicating hollow work supporting arm extending horizontally therefrom and a communicating hollow standard sustaining a needle arm 'over the work supporting arm; a needle .shaft extending lengthwise of the needle arm into the hollow of the standard; a looper shaft extending lengthwise of the interior of the work arm in parallel relation to the needle shaft; a drive shaft journaled in the frame base crosswise of the needle shaft and the looper shaft in a plane below the'latter and having a rotary eccentric actuator thereon; pitmans extending upward from said rotary actuator within the hollows of the column and the base to the needle and looper shafts respectively to simultaneously operate said shafts; and an oil sump in the base from which oil is taken and splashed about by said rotary actuator vto lubricate the enclosed parts.

12. The invention according to claim 11, in which 4one end of the drive shaft protrudes through an oil-sealed bearing at one side of the base; and wherein the rotor of a looper thread 'control means is mounted on the protruding end of said ldrive shaft.

13. In a feed-on-the-arm sewing machine having a 'frame with a work supporting arm along which the work is fed, feeding means including a feed bar which extends lengthwise of the work supporting arm; a drive shaft disposed below and crosswise of the feed bar, and having a pair of eccentric actuators thereon; a rocker pivoted on the work supporting arm. and having a pair of arms extending upward from the pivot for movement in the same direction, with one of said arms connected to the rear end of the feed bar; a link connecting one of the eccentric actuators to the other arm of the rocker so that lengthwise tension is induced both in said bar and in said link during the advancing movements of the feed bar; a rocker pivoted on the work supporting arm and having-a pair of arms respectively extending horizontally-and upward from its pivot, with its horizontal arm connected to the front end of the feed bar, and another link connecting the other eccentric actuator to the upstanding arm of the last mentioned rocker so that lengthwise tension is induced therein during the lift movements of said feed bar.

14. In a feed-on-the-arm sewing machine having a base. with .a laterally-extending work supporting arm along which the work is fed, feeding means including a feed bar which extends lengthlwise of the work supporting arm; a rocker pivoted i latter so as to =be under lengthwise tension during the advancing movements of said feed bar.

. y FREDERICK LUTZ. 

